J-PARC and Dimuon Experiments

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J-PARC and Dimuon Experiments

• Shinya Sawada
• KEK
• (High Energy Accelerator Research Organization,
  Japan)

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J-PARC Facility

• The budget for about 2/3 of the entire project
  has been approved by the Japanese government from
  JFY2001 as Phase 1.
• Phase 1 (151 billion Yen) consists of major
  accelerator components and a part of experimental
  facilities.

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LINAC
RCS
n
MLF
50GeV-PS
Hd
Birds eye photo in Feb. 2008
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Acceleration and Extraction at 3 GeV

• 2007.10.31.14h03m23s

500ns
Beam Current inside the Ring
Beams remain inside the ring for 20 ms.
Current
Beam Loss
Time
3NBT Beam Current (Extracted Beams)
Magnetic Field
3GeV
Current
20 ms
Injection at the minimum field and the extraction
at the maximum field
Beam Current Detected at 3NBT
Time
181MeV
Successful Acceleration and Extraction !!!
Acceleration
Injection
Extraction
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Performance of the 50-GeV PS
Numbers in red are design values.
Numbers in parentheses are ones for the beginning
of Phase 1. Energy recovery of the linac to 400
MeV is planned just after the completion of the
Phase-1 construction in 2009.

• Beam Energy 50GeV ELinac 400MeV
• (30GeV for Slow Beam) ELinac (180MeV)
• (30GeV for Fast Beam)
• Repetition 3.4 5-6s
• Flat Top Width 0.7 2-3s
• Beam Intensity 3.3x1014ppp, 15mA
• (21014ppp, 9mA)
• Beam Power 750kW
• (270kW)

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Slow Extraction Beamline (Phase 1)
NP-HALL 56m(L)60m(W)
50-GeV PS
A-Line
Switch Yard
T1 Target 30 Loss
Split Point 2 Loss
T0 Target 0.5 Loss
Beam Dump 750kW
Plan to extend the hall downstream (50m) in the
Phase 2.
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Hadron Hall July 2007
??????????????????????????
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Beamlines at the Hadron Hall
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Hadron Hall Today
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Hadron Experimental Hall (Phase I)
A-Line
Beam Dump
Extension in Phase II
56 m
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Oct.
Dec.
Neutrino
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Important Schedule

• May-June, 2008 Beam injection to the 50-GeV
  synchrotron and trial of beam capture
• Summer, 2008 Installation of slow extraction
  equipments
• December 2008 Acceleration up to 30 GeV and the
  first slow extraction to the Hadron facility
• December, 2008 February, 2009 First
  experiments using slow extracted proton beam at
  K1.8BR
• April, 2009 First neutrino production

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Results of the 4th PAC (Jan 2008)
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Measurement of High-Mass dimuon Production at
J-PARC (P-04)
Collaboration
Abilene Christian University, Argonne National
Laboratory, Duke University, High
Energy Accelerator Research Organization,
University of Illinois at Urbana-Champaign, Kyoto
University, Los Alamos National
Laboratory, Pusan National University, RIKEN,
Seoul National University, Tokyo Institute of
Technology, Tokyo University of
Science, Yamagata University
Collaboration members
J.K. Ahn, J. Chiba, Seonho Choi, D. Dutta, H.
Gao, Y. Goto, L.D. Isenhower, T. Iwata, S.
Kato,M.J. Leitch, M.X. Liu, P.L. McGaughey, J.C.
Peng, P. Reimer, M. Sadler, N. Saito, S.
Sawada,T.-A. Shibata, K.H. Tanaka, R. Towell,
H.Y. Yoshida
(Spokesperson S. Sawada and J. C. Peng)
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(A part of) Physics with Dimuon Measuremet at
J-PARC
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dbar/ubar at larger x
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PAC Message on P04
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Prospect and Relation with E906

• Major equipments of E906 will be shipped to
  J-PARC after E906, in 2012?
• Radiation especially of M1 be OK? Core part of
  the beam dump can be built as a separate module?
• Beamline for P04 has not been funded, and we
  continue to make efforts.
• The beam energy would be 30 GeV at the beginning
  of the J-PARC experiments.
• Physics cases even after E906 should be more
  emphasized, such as spin related measurements
  even without polarized beam and/or target.
• Discussion on responsibilities of P04 and
  modified P24 would be important.

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Polarized Proton Acceleration at J-PARC (P24)
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Status of P24

• PAC
• No decision yet.
• Although the PAC recognizes that polarized beam
  acceleration in the MR can be one of the future
  options in J-PARC, judgement of the technical
  feasibility of this proposal is beyond the
  present PACs scope
• The PAC would like to hear a separate proposal
  with more specific discussion of the physics and
  proposed measurements
• Revised P24 (or another number), with physics
  emphasis, will be submitted to the next PAC
  meeting (October 2008).

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Hadron hall Users Association

• Hadron hall Users Association HUA was
  founded in March, 2007.
• Now the Chair of HUA is a member of J-PARC Users
  Steering Committee
• Send email to hua-sec_at_rcnp.osaka-u.ac.jp to join.

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Users Steering Committee

• New members were elected in November of 2007.
• Representatives from four communities are
  included.
• Roadmap of the future J-PARC will be discussed at
  this committee.
• Discussion items by this committee were
  re-identified.
• The committee will start intense discussions from
  February about future plans of the J-PARC.

Phase 2 for J-PARC will be discussed first at
this Committee
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Summary

• J-PARC has achieved 3-GeV beams at RCS and the
  50-GeV synchrotron already.
• The first 30-GeV slow extracted beam is expected
  around the end of this year.
• Our proposals, P04 for unpol. dimuon measurement
  and P24 for pol. proton acceleration with
  experiments, are deferred.
• HUA has been founded. Your participation is very
  much welcome.